/*
 * Copyright 2011-17 Fraunhofer ISE, energy & meteo Systems GmbH and other contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
package org.openmuc.josistack;

import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;

/**
 * Simple InputStream wrapper around a {@link ByteBuffer} object
 * 
 * @author Karsten Mueller-Bier
 */
public final class ByteBufferInputStream extends InputStream {

    private final ByteBuffer buf;

    public ByteBufferInputStream(ByteBuffer buf) {
        this.buf = buf;
    }

    @Override
    public int read() throws IOException {
        if (buf.hasRemaining() == false) {
            return -1;
        }
        return buf.get() & 0xFF;
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        if (buf.hasRemaining() == false) {
            return -1;
        }
        int size = Math.min(len, available());

        buf.get(b, off, size);
        return size;
    }

    @Override
    public int available() throws IOException {
        return buf.limit() - buf.position();
    }
}
